Bootstrap is a Front-End Framework, that works using HTML, CSS and JavaScript.

Personally, I did not recommend that your start your learning using Frameworks, cause it’s hard to understand what the code is doing. First, study the language from the basics to not get confused.

I don’t use Bootstrap, but if your interest about how to starting to create websites, it’s a good option to facilitate your work. In course we have examples of implementations of how to use Bootstrap to create Responsive Websites.

For me, the best part of this course was the JavaScript, as it has a good introduction and basic functionalities, it helped me to improve my learning. For other way, they use handlebars.js to create some functions (which I think is more complicated than just do it with jQuery – the one that I prefer to use).